Enclosures for electronic circuitry typically include a case or housing, a cover, a seal between the housing and the cover, and fasteners for attaching the cover to the housing. Usually, the housing and cover are made of an electrically conductive material (e.g., metal) and have matching shapes, e.g., a square shape. To assemble a conventional electronics enclosure, adhesive is applied near the perimeter of the housing. The cover is placed on top the adhesive surface. Fasteners are threaded through the cover, adhesive and housing to affix the cover to the housing and to establish electrical interconnection between the cover and the housing. The electrical interconnection at the fasteners provides direct current (DC) and radio frequency (RF) grounds in the fastener locations around the perimeter of the housing. The adhesive creates an environmental seal between the cover and housing. Enclosures for electronic circuitry without a seal are also well-known in the art.
Currently available electronic enclosures typically use four fasteners to secure a cover to a housing and to thus complete electrical continuity between the cover and the housing. One example of a conventional prior art electronic enclosure is shown in a cross-sectional view in FIG. 5. The generally square electronic enclosure 50 in FIG. 5 does not have an optimal continuous electronic ground contact surface between housing 51 and cover 52. Threaded fastener 53 passes between cover 52, adhesive 54, and housing 51. The exemplary conventional enclosure 50 has four fasteners (fastener 53 and three fasteners that are not shown) that are generally located at each of the four corners of enclosure 50. Fastener 53 and the three fasteners that are not shown provide electrical continuity between cover 52 and housing 51. Adhesive 56 is located between the product circuit board 55 and the product circuit board support 61 to adhere the assembly together. A ground pin 57 is attached to product circuit board 55 at interconnect 58. Ground pin 57 provides electrical conductivity between circuit board 55 and housing 51 so that circuit board 55 and housing 51 are at the same voltage potential. The adhesive 54 of enclosure 50 acts as a seal to keep contaminants out of the electronic enclosure.
The method of assembly of the conventional electronic enclosure 50 typically includes assembling electronics in the housing 51, dispensing adhesive 54 continuously along the perimeter of the housing 51, laying the cover 52 on the adhesive 54 surface 59, and passing fastener 53 and the three fasteners that are not shown through the cover 52 and into the housing 51 through adhesive 54. Typically, a machine tool will compress the cover 52 onto the seal surface 59 of adhesive 54. Thereafter, the cover 52 is fastened down with fasteners 53 and the three fasteners that are not shown.
Known electronic enclosures often are generally not efficient. The use of separate fasteners to affix the cover to the housing complicates the assembly process of the cover to the housing. Further, separate fasteners limit the amount of electrical continuity between the cover and the housing. The arrangement of the fasteners, the cover, and the housing results in difficult dispersion of adhesive between the cover and the housing and does not provide optimal seal integrity. Repair of an enclosure with four separate fasteners, a housing, a cover, and a seal is difficult.
Accordingly, it is therefore desirable to provide for an electronic enclosure with continuous electrical ground contact surface that may solve the aforementioned problems and provide conductive efficiency, grounding, sealing, assembly and repairability advantages over a conventional electronic enclosure.